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Fulltext In vitro alpha-glucosidase and alpha-amylase enzyme inhibitory effects of Andrographis paniculata extract and andrographolide

Subramanian R, Asmawi MZ, Sadikun A

Acta Biochim. Pol., 2008;55(2):391-8.
PMID: 18511986

There has been an enormous interest in the development of alternative medicines for type 2 diabetes, specifically screening for phytochemicals with the ability to delay or prevent glucose absorption. The goal of the present study was to provide in vitro evidence for potential inhibition of alpha-glucosidase and alpha-amylase enzymes, followed by a confirmatory in vivo study on rats to generate a stronger biochemical rationale for further studies on the ethanolic extract of Andrographis paniculata and andrographolide. The extract showed appreciable alpha-glucosidase inhibitory effect in a concentration-dependent manner (IC(50)=17.2+/-0.15 mg/ml) and a weak alpha-amylase inhibitory activity (IC(50)=50.9+/-0.17 mg/ml). Andrographolide demonstrated a similar (IC(50)=11.0+/-0.28 mg/ml) alpha-glucosidase and alpha-amylase inhibitory activity (IC(50)=11.3+/-0.29 mg/ml). The positive in vitro enzyme inhibition tests paved way for confirmatory in vivo studies. The in vivo studies demonstrated that A. paniculata extract significantly (P<0.05) reduced peak blood glucose and area under curve in diabetic rats when challenged with oral administration of starch and sucrose. Further, andrographolide also caused a significant (P<0.05) reduction in peak blood glucose and area under the curve in diabetic rats. Hence alpha-glucosidase inhibition may possibly be one of the mechanisms for the A. paniculata extract to exert antidiabetic activity and indicates that AP extract can be considered as a potential candidate for the management of type 2 diabetes mellitus.

Matched MeSH terms: Blood Glucose/metabolism
Comparative study of two insulin regimes in pregnancy complicated by diabetes mellitus

Nor Azlin MI, Nor NA, Sufian SS, Mustafa N, Jamil MA, Kamaruddin NA

Acta Obstet Gynecol Scand, 2007;86(4):407-8.
PMID: 17486460
Matched MeSH terms: Blood Glucose/metabolism
Fulltext Ultrastructure of the liver microcirculation influences hepatic and systemic insulin activity and provides a mechanism for age-related insulin resistance

Mohamad M, Mitchell SJ, Wu LE, White MY, Cordwell SJ, Mach J, et al.

Aging Cell, 2016 08;15(4):706-15.
PMID: 27095270 DOI: 10.1111/acel.12481

While age-related insulin resistance and hyperinsulinemia are usually considered to be secondary to changes in muscle, the liver also plays a key role in whole-body insulin handling and its role in age-related changes in insulin homeostasis is largely unknown. Here, we show that patent pores called 'fenestrations' are essential for insulin transfer across the liver sinusoidal endothelium and that age-related loss of fenestrations causes an impaired insulin clearance and hyperinsulinemia, induces hepatic insulin resistance, impairs hepatic insulin signaling, and deranges glucose homeostasis. To further define the role of fenestrations in hepatic insulin signaling without any of the long-term adaptive responses that occur with aging, we induced acute defenestration using poloxamer 407 (P407), and this replicated many of the age-related changes in hepatic glucose and insulin handling. Loss of fenestrations in the liver sinusoidal endothelium is a hallmark of aging that has previously been shown to cause deficits in hepatic drug and lipoprotein metabolism and now insulin. Liver defenestration thus provides a new mechanism that potentially contributes to age-related insulin resistance.

Matched MeSH terms: Glucose/metabolism
Sugar-sweetened carbonated beverage consumption and coronary artery calcification in asymptomatic men and women

Chun S, Choi Y, Chang Y, Cho J, Zhang Y, Rampal S, et al.

Am Heart J, 2016 07;177:17-24.
PMID: 27297845 DOI: 10.1016/j.ahj.2016.03.018

BACKGROUND: Sugar-sweetened carbonated beverage consumption has been linked to obesity, metabolic syndrome, type 2 diabetes, and clinically manifest coronary heart disease, but its association with subclinical coronary heart disease remains unclear. We investigated the relationship between sugar-sweetened carbonated beverage consumption and coronary artery calcium (CAC) in a large study of asymptomatic men and women.
METHODS: This was a cross-sectional study of 22,210 adult men and women who underwent a comprehensive health screening examination between 2011 and 2013 (median age 40 years). Sugar-sweetened carbonated beverage consumption was assessed using a validated food frequency questionnaire, and CAC was measured by cardiac computed tomography. Multivariable-adjusted CAC score ratios and 95% CIs were estimated from robust Tobit regression models for the natural logarithm (CAC score +1).
RESULTS: The prevalence of detectable CAC (CAC score >0) was 11.7% (n = 2,604). After adjustment for age; sex; center; year of screening examination; education level; physical activity; smoking; alcohol intake; family history of cardiovascular disease; history of hypertension; history of hypercholesterolemia; and intake of total energy, fruits, vegetables, and red and processed meats, only the highest category of sugar-sweetened carbonated beverage consumption was associated with an increased CAC score compared with the lowest consumption category. The multivariable-adjusted CAC ratio comparing participants who consumed ≥5 sugar-sweetened carbonated beverages per week with nondrinkers was 1.70 (95% CI, 1.03-2.81). This association did not differ by clinical subgroup, including participants at low cardiovascular risk.
CONCLUSION: Our findings suggest that high levels of sugar-sweetened carbonated beverage consumption are associated with a higher prevalence and degree of CAC in asymptomatic adults without a history of cardiovascular disease, cancer, or diabetes.

Matched MeSH terms: Blood Glucose/metabolism
Fulltext Associations of gestational cardiovascular health with pregnancy outcomes: the Hyperglycemia and Adverse Pregnancy Outcome study

Perak AM, Lancki N, Kuang A, Labarthe DR, Allen NB, Shah SH, et al.

Am J Obstet Gynecol, 2021 02;224(2):210.e1-210.e17.
PMID: 32768430 DOI: 10.1016/j.ajog.2020.07.053

BACKGROUND: The American Heart Association's formal characterization of cardiovascular health combines several metrics in a health-oriented, rather than disease-oriented, framework. Although cardiovascular health assessment during pregnancy has been recommended, its significance for pregnancy outcomes is unknown.
OBJECTIVE: The purpose of this study was to examine the association of gestational cardiovascular health-formally characterized by a combination of 5 metrics-with adverse maternal and newborn outcomes.
STUDY DESIGN: We analyzed data from the Hyperglycemia and Adverse Pregnancy Outcome study, including 2304 mother-newborn dyads from 6 countries. Maternal cardiovascular health was defined by the combination of the following 5 metrics measured at a mean of 28 (24-32) weeks' gestation: body mass index, blood pressure, lipids, glucose, and smoking. Levels of each metric were categorized using pregnancy guidelines, and the total cardiovascular health was scored (0-10 points, where 10 was the most favorable). Cord blood was collected at delivery, newborn anthropometrics were measured within 72 hours, and medical records were abstracted for obstetrical outcomes. Modified Poisson and multinomial logistic regression were used to test the associations of gestational cardiovascular health with pregnancy outcomes, adjusted for center and maternal and newborn characteristics.
RESULTS: The average age of women at study exam was 29.6 years old, and they delivered at a mean gestational age of 39.8 weeks. The mean total gestational cardiovascular health score was 8.6 (of 10); 36.3% had all ideal metrics and 7.5% had 2+ poor metrics. In fully adjusted models, each 1 point higher (more favorable) cardiovascular health score was associated with lower risks for preeclampsia (relative risk, 0.67 [95% confidence interval, 0.61-0.73]), unplanned primary cesarean delivery (0.88 [0.82-0.95]), newborn birthweight >90th percentile (0.81 [0.75-0.87]), sum of skinfolds >90th percentile (0.84 [0.77-0.92]), and insulin sensitivity <10th percentile (0.83 [0.77-0.90]). Cardiovascular health categories demonstrated graded associations with outcomes; for example, relative risks (95% confidence intervals) for preeclampsia were 3.13 (1.39-7.06), 5.34 (2.44-11.70), and 9.30 (3.95-21.86) for women with ≥1 intermediate, 1 poor, or ≥2 poor (vs all ideal) metrics, respectively.
CONCLUSION: More favorable cardiovascular health at 24 to 32 weeks' gestation was associated with lower risks for several adverse pregnancy outcomes in a multinational cohort.

Matched MeSH terms: Blood Glucose/metabolism*
Skeletal muscle glucose uptake during treadmill exercise in neuronal nitric oxide synthase-μ knockout mice

Hong YH, Yang C, Betik AC, Lee-Young RS, McConell GK

Am J Physiol Endocrinol Metab, 2016 05 15;310(10):E838-45.
PMID: 27006199 DOI: 10.1152/ajpendo.00513.2015

Nitric oxide influences intramuscular signaling that affects skeletal muscle glucose uptake during exercise. The role of the main NO-producing enzyme isoform activated during skeletal muscle contraction, neuronal nitric oxide synthase-μ (nNOSμ), in modulating glucose uptake has not been investigated in a physiological exercise model. In this study, conscious and unrestrained chronically catheterized nNOSμ(+/+) and nNOSμ(-/-) mice either remained at rest or ran on a treadmill at 17 m/min for 30 min. Both groups of mice demonstrated similar exercise capacity during a maximal exercise test to exhaustion (17.7 ± 0.6 vs. 15.9 ± 0.9 min for nNOSμ(+/+) and nNOSμ(-/-), respectively, P > 0.05). Resting and exercise blood glucose levels were comparable between the genotypes. Very low levels of NOS activity were detected in skeletal muscle from nNOSμ(-/-) mice, and exercise increased NOS activity only in nNOSμ(+/+) mice (4.4 ± 0.3 to 5.2 ± 0.4 pmol·mg(-1)·min(-1), P < 0.05). Exercise significantly increased glucose uptake in gastrocnemius muscle (5- to 7-fold) and, surprisingly, more so in nNOSμ(-/-) than in nNOSμ(+/+) mice (P < 0.05). This is in parallel with a greater increase in AMPK phosphorylation during exercise in nNOSμ(-/-) mice. In conclusion, nNOSμ is not essential for skeletal muscle glucose uptake during exercise, and the higher skeletal muscle glucose uptake during exercise in nNOSμ(-/-) mice may be due to compensatory increases in AMPK activation.

Matched MeSH terms: Blood Glucose/metabolism*; Glucose/metabolism
Fulltext Glucose uptake and lipid metabolism are impaired in epicardial adipose tissue from heart failure patients with or without diabetes

Burgeiro A, Fuhrmann A, Cherian S, Espinoza D, Jarak I, Carvalho RA, et al.

Am J Physiol Endocrinol Metab, 2016 Apr 01;310(7):E550-64.
PMID: 26814014 DOI: 10.1152/ajpendo.00384.2015

Type 2 diabetes mellitus is a complex metabolic disease, and cardiovascular disease is a leading complication of diabetes. Epicardial adipose tissue surrounding the heart displays biochemical, thermogenic, and cardioprotective properties. However, the metabolic cross-talk between epicardial fat and the myocardium is largely unknown. This study sought to understand epicardial adipose tissue metabolism from heart failure patients with or without diabetes. We aimed to unravel possible differences in glucose and lipid metabolism between human epicardial and subcutaneous adipocytes and elucidate the potential underlying mechanisms involved in heart failure. Insulin-stimulated [(14)C]glucose uptake and isoproterenol-stimulated lipolysis were measured in isolated epicardial and subcutaneous adipocytes. The expression of genes involved in glucose and lipid metabolism was analyzed by reverse transcription-polymerase chain reaction in adipocytes. In addition, epicardial and subcutaneous fatty acid composition was analyzed by high-resolution proton nuclear magnetic resonance spectroscopy. The difference between basal and insulin conditions in glucose uptake was significantly decreased (P= 0.006) in epicardial compared with subcutaneous adipocytes. Moreover, a significant (P< 0.001) decrease in the isoproterenol-stimulated lipolysis was also observed when the two fat depots were compared, and it was strongly correlated with lipolysis, lipid storage, and inflammation-related gene expression. Moreover, the fatty acid composition of these tissues was significantly altered by diabetes. These results emphasize potential metabolic differences between both fat depots in the presence of heart failure and highlight epicardial fat as a possible therapeutic target in situ in the cardiac microenvironment.

Matched MeSH terms: Blood Glucose/metabolism*; Glucose/metabolism
Fulltext The JCR:LA-cp rat: a novel rodent model of cystic medial necrosis

Pung YF, Chilian WM, Bennett MR, Figg N, Kamarulzaman MH

Am J Physiol Heart Circ Physiol, 2017 Mar 01;312(3):H541-H545.
PMID: 27986661 DOI: 10.1152/ajpheart.00653.2016

Although there are multiple rodent models of the metabolic syndrome, very few develop vascular complications. In contrast, the JCR:LA-cp rat develops both metabolic syndrome and early atherosclerosis in predisposed areas. However, the pathology of the normal vessel wall has not been described. We examined JCR:LA control (+/+) or cp/cp rats fed normal chow diet for 6 or 18 mo. JCR:LA-cp rats developed multiple features of advanced cystic medial necrosis including "cysts," increased collagen formation and proteoglycan deposition around cysts, apoptosis of vascular smooth muscle cells, and spotty medial calcification. These appearances began within 6 mo and were extensive by 18 mo. JCR:LA-cp rats had reduced medial cellularity, increased medial thickness, and vessel hypoxia that was most marked in the adventitia. In conclusion, the normal chow-fed JCR:LA-cp rat represents a novel rodent model of cystic medial necrosis, associated with multiple metabolic abnormalities, vascular smooth muscle cell apoptosis, and vessel hypoxia.NEW & NOTEWORTHY Triggers for cystic medial necrosis (CMN) have been difficult to study due to lack of animal models to recapitulate the pathologies seen in humans. Our study is the first description of CMN in the rat. Thus the JCR:LA-cp rat represents a useful model to investigate the underlying molecular changes leading to the development of CMN.

Matched MeSH terms: Blood Glucose/metabolism
Fulltext No effect of NOS inhibition on skeletal muscle glucose uptake during in situ hindlimb contraction in healthy and diabetic Sprague-Dawley rats

Hong YH, Betik AC, Premilovac D, Dwyer RM, Keske MA, Rattigan S, et al.

Am J Physiol Regul Integr Comp Physiol, 2015 May 15;308(10):R862-71.
PMID: 25786487 DOI: 10.1152/ajpregu.00412.2014

Nitric oxide (NO) has been shown to be involved in skeletal muscle glucose uptake during contraction/exercise, especially in individuals with Type 2 diabetes (T2D). To examine the potential mechanisms, we examined the effect of local NO synthase (NOS) inhibition on muscle glucose uptake and muscle capillary blood flow during contraction in healthy and T2D rats. T2D was induced in Sprague-Dawley rats using a combined high-fat diet (23% fat wt/wt for 4 wk) and low-dose streptozotocin injections (35 mg/kg). Anesthetized animals had one hindlimb stimulated to contract in situ for 30 min (2 Hz, 0.1 ms, 35 V) with the contralateral hindlimb rested. After 10 min, the NOS inhibitor, N(G)-nitro-l-arginine methyl ester (l-NAME; 5 μM) or saline was continuously infused into the femoral artery of the contracting hindlimb until the end of contraction. Surprisingly, there was no increase in skeletal muscle NOS activity during contraction in either group. Local NOS inhibition had no effect on systemic blood pressure or muscle contraction force, but it did cause a significant attenuation of the increase in femoral artery blood flow in control and T2D rats. However, NOS inhibition did not attenuate the increase in muscle capillary recruitment during contraction in these rats. Muscle glucose uptake during contraction was significantly higher in T2D rats compared with controls but, unlike our previous findings in hooded Wistar rats, NOS inhibition had no effect on glucose uptake during contraction. In conclusion, NOS inhibition did not affect muscle glucose uptake during contraction in control or T2D Sprague-Dawley rats, and this may have been because there was no increase in NOS activity during contraction.

Matched MeSH terms: Glucose/metabolism*
Association of metabolic syndrome with testosterone and inflammation in men

Wickramatilake CM, Mohideen MR, Pathirana C

Ann Endocrinol (Paris), 2015 Jul;76(3):260-3.
PMID: 26142486 DOI: 10.1016/j.ando.2015.04.008

OBJECTIVE: There is limited data on the assessment of relationship between sex hormones, metabolic syndrome (MS) and inflammation. Therefore, our objective was to examine the relationship between metabolic syndrome, testosterone and inflammation.
PATIENTS AND METHODS: It was a cross-sectional study which included 309 subjects in the age range of 30-70years. Blood was analyzed for plasma glucose, serum lipids, total testosterone (TT) and high-sensitivity C-reactive protein (hs-CRP).
RESULTS: There were 153 patients with metabolic syndrome and 156 without MS according to modified NCEP guidelines. Age, BMI, obesity, dyslipidaemia, smoking (OR=2.35, CI=1.35-4.09), LDL-Ch, low TT (OR=0.76, CI=0.38-1.52) and elevated hs-CRP (OR=1.56, CI=0.87-2.80) were significant independent predictors of MS (all P<0.05).
CONCLUSIONS: The low testosterone and high hs-CRP levels are independent predictors of metabolic syndrome.
KEYWORDS: Hommes; Inflammation; Men; Metabolic syndrome; Syndrome métabolique; Testosterone; Testostérone

Matched MeSH terms: Blood Glucose/metabolism
Fulltext Insulin resistance using HOMA model in obstructive sleep apnea: a cross sectional study

Azman M, Sani A, Kamaruddin NA

Ann Saudi Med, 2014;34(6):476-81.
PMID: 25971819 DOI: 10.5144/0256-4947.2014.476

BACKGROUND AND OBJECTIVES: Obstructive sleep apnea (OSA) is a common disease affecting middle-aged patients and is associated with significant cardiovascular, cerebrovascular, and metabolic complications. Current evidences show inconclusive association between OSA and insulin resistance (IR). This study aims to examine the possible correlation between OSA parameters and IR.
DESIGN AND SETTINGS: This was a cross-sectional study to examine the association between OSA parameters and IR using homeostasis model assessment (HOMA) on patients who underwent polysomnogram (PSG) in a tertiary center between March 2011 and March 2012 (1 year).
PATIENTS AND METHODS: A total of 62 patients underwent PSG within the study period, of which 16 patients were excluded due to abnormal fasting blood sugar. Information on patients' medical illnesses, medications, and Epworth sleepiness scale (ESS) was obtained. Patients' body mass index (BMI), neck circumference, and waist circumference (WC) were measured. Blood samples were collected after 8 hours of fasting to measure HOMA-IR value. Overnight PSG was performed for all patients. Data was recorded and analyzed using SPSS, version 12.0 (SPSS Inc, Chicago, USA).
RESULTS: The prevalence of IR in OSA patients was 64.3%. There was significant correlation between OSA parameters (apnea-hypopnea index, ESS, BMI, and WC) and HOMA-IR with correlation coefficient of 0.529, 0.224, 0.261, and 0.354, respectively.
CONCLUSION: A linear correlation exists between OSA parameters and IR concluding a definite causal link between OSA and IR. IR screening is recommended in severe OSA patients.

Matched MeSH terms: Blood Glucose/metabolism*
Findings among 100 type 2 diabetics in a clinic in Penang, Malaysia, 1983-84

Merriman A, Ross I

Ann Acad Med Singap, 1985 Apr;14(2):277-85.
PMID: 4037686

A Specialist Clinic was commenced in August 1983, from the Medical School at Universiti Sains Malaysia, Penang, Malaysia to assess: 1) the present control and 2) the incidence of complications in a diabetic population already receiving primary health care at Penang General Hospital. The ethnic groups among the diabetics were Chinese (39%), Malays (26%) and Indian (35%). There was a greater percentage of Indians than would be expected from the ethnic distribution of the population of Penang. The results of the first 100 (43 males and 57 females) non-insulin dependent diabetic patients are reviewed. The mean age was 54 years, 41% had relatives with diabetes, and all were taking oral agents. The diet comprehension and compliance were poor. 65% of the group, 54% of males and 75% of females were obese. The mean blood glucose was 11 m.mols/l (fasting) and 12.8 m.mols/1 (2 hours post prandial). The complications seen in the 100 diabetics were: albuminurea 41, skin infection 37, cataracts 35, hypertension 32, peripheral sensory neuropathy 32, retinopathy 22, ischaemic heart disease 19, autonomic neuropathy 10, impaired renal function 4 (urea or creatinine elevated), foot ulcer 2 and gangrene 1. Urinalysis for glucose at the Clinic showed very little correlation with blood glucose at the same time. Nine out of 43 males admitted to impotence on questioning. Comparisons of findings in Penang were made with recent studies in Singapore and Hong Kong.

Matched MeSH terms: Blood Glucose/metabolism
The variation of glucose tolerance in a multi racial population

Ch'ng SL, Chandrasekharan N

Ann Acad Med Singap, 1985 Apr;14(2):223-8.
PMID: 4037680

The pattern of plasma and urine sugar changes after 50g glucose load in 1900 Malaysians (522 males and 1378 females) consisting predominantly of Malays, Chinese and Indians were studied. The data were analysed using Statistical Package for Social Sciences (SPSS). The results show bimodal distribution of 120 min. plasma sugar values in the age groups 21 years and above and trimodal distribution in most groups above 40 years. The mean 120 minutes plasma sugar cut-off values for nondiabetics (ND), impaired glucose tolerance (IGT), and diabetics (DM) of 8.4 and 11.1 mmol/l respectively were close to the values recommended by the National Diabetic Data Group (NDDG). Fifty two percent of all subjects showed peaked plasma sugar values at 60 minutes (14% of them had IGT, 12% DM), 25% peaked at 30 minutes (98% of them were ND). The rest showed peaked values at 90 minutes (17%), 120 minutes (4%) and 150 minutes (2%) and from this group forty two percent were DM and 23% had IGT. Reliance on urine sugar qualitative tests could misclassify 7.3% of subjects (predominantly elderly females) with hyperglycaemia of greater than 11 mmol/l. This study shows that in the 50 g glucose tolerance test, the NDDG criteria for ND, IGT, DM is still applicable to the Malaysian population. The sampling time could be reduced to four points at 0, 60, 90, and 120 minutes. Blood analysis is the preferred method for the diagnosis of hyperglycaemia in elderly females.

Matched MeSH terms: Blood Glucose/metabolism*
Insulin-dependent diabetes mellitus: strategy for prevention and management

Wong HB

Ann Acad Med Singap, 1985 Apr;14(2):334-42.
PMID: 4037695

Insulin-dependent diabetes mellitus (IDDM) is inherited in a multifactorial manner with polygenes and environmental factors contributing to its emergence in a particular individual. The evidence for such a mode of inheritance is reviewed. One of the most important genetic roles is that played by the HLA genes on chromosome 6 and the different alleles which increase or decrease susceptibility in Caucasians, Japanese, Singapore Chinese and Shanghai Chinese are described. It is inferred that these alleles are different in different ethnic groups. The other genes which are important are unknown. The environmental influences are less well known although viral infections may act as triggers. Because the morbidity and mortality are still extremely serious in IDDM patients in spite of insulin therapy, it is proposed that preventive measures should be instituted in families prone to IDDM. The role of prenatal diagnosis is discussed especially in those families with multiple HLA susceptibility genes present. Great care paid to management of hyperglycemia from onset of the disease may reduce future morbidity and mortality.

Matched MeSH terms: Blood Glucose/metabolism
Effect of altered eating pattern on serum fructosamine: total protein ratio and plasma glucose level

Ch'ng SL, Cheah SH, Husain R, Duncan MT

Ann Acad Med Singap, 1989 May;18(3):326-7.
PMID: 2774480

The effect of alteration of eating pattern during Ramadan on body mass index (BMI), serum fructosamine: total protein ratio (F/TP), and glucose level in 18 healthy male Asiatic Moslems were studied. The results showed a significant decrease (p less than 0.025) in F/TP at the second week of Ramadan in 11 subjects who experienced continuous decrease in BMI throughout Ramadan. The remaining 7 subjects showed no significant changes in BMI and F/TP. No evidence of hypoglycaemia was observed in the subjects during the study. Serum fructosamine: total protein ratio in subjects with altered eating pattern preferably should be interpreted along with the change in body mass index.

Matched MeSH terms: Blood Glucose/metabolism*
Metformin synergizes 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) combination therapy through impairing intracellular ATP production and DNA repair in breast cancer stem cells

Soo JS, Ng CH, Tan SH, Malik RA, Teh YC, Tan BS, et al.

Apoptosis, 2015 Oct;20(10):1373-87.
PMID: 26276035 DOI: 10.1007/s10495-015-1158-5

Metformin, an AMPK activator, has been reported to improve pathological response to chemotherapy in diabetic breast cancer patients. To date, its mechanism of action in cancer, especially in cancer stem cells (CSCs) have not been fully elucidated. In this study, we demonstrated that metformin, but not other AMPK activators (e.g. AICAR and A-769662), synergizes 5-fluouracil, epirubicin, and cyclophosphamide (FEC) combination chemotherapy in non-stem breast cancer cells and breast cancer stem cells. We show that this occurs through an AMPK-dependent mechanism in parental breast cancer cell lines. In contrast, the synergistic effects of metformin and FEC occurred in an AMPK-independent mechanism in breast CSCs. Further analyses revealed that metformin accelerated glucose consumption and lactate production more severely in the breast CSCs but the production of intracellular ATP was severely hampered, leading to a severe energy crisis and impairs the ability of CSCs to repair FEC-induced DNA damage. Indeed, addition of extracellular ATP completely abrogated the synergistic effects of metformin on FEC sensitivity in breast CSCs. In conclusion, our results suggest that metformin synergizes FEC sensitivity through distinct mechanism in parental breast cancer cell lines and CSCs, thus providing further evidence for the clinical relevance of metformin for the treatment of cancers.

Matched MeSH terms: Glucose/metabolism
Oil palm empty fruit bunch as alternative substrate for acetone-butanol-ethanol production by Clostridium butyricum EB6

Ibrahim MF, Abd-Aziz S, Razak MN, Phang LY, Hassan MA

Appl Biochem Biotechnol, 2012 Apr;166(7):1615-25.
PMID: 22391689 DOI: 10.1007/s12010-012-9538-6

Acetone-butanol-ethanol (ABE) production from renewable resources has been widely reported. In this study, Clostridium butyricum EB6 was employed for ABE fermentation using fermentable sugar derived from treated oil palm empty fruit bunch (OPEFB). A higher amount of ABE (2.61 g/l) was produced in a fermentation using treated OPEFB as the substrate when compared to a glucose based medium that produced 0.24 g/l at pH 5.5. ABE production was increased to 3.47 g/l with a yield of 0.24 g/g at pH 6.0. The fermentation using limited nitrogen concentration of 3 g/l improved the ABE yield by 64%. The study showed that OPEFB has the potential to be applied for renewable ABE production by C. butyricum EB6.

Matched MeSH terms: Glucose/metabolism
Production of lipids containing high levels of docosahexaenoic acid by a newly isolated microalga, Aurantiochytrium sp. KRS101

Hong WK, Rairakhwada D, Seo PS, Park SY, Hur BK, Kim CH, et al.

Appl Biochem Biotechnol, 2011 Aug;164(8):1468-80.
PMID: 21424706 DOI: 10.1007/s12010-011-9227-x

In the present study, a novel oleaginous Thraustochytrid containing a high content of docosahexaenoic acid (DHA) was isolated from a mangrove ecosystem in Malaysia. The strain identified as an Aurantiochytrium sp. by 18S rRNA sequencing and named KRS101 used various carbon and nitrogen sources, indicating metabolic versatility. Optimal culture conditions, thus maximizing cell growth, and high levels of lipid and DHA production, were attained using glucose (60 g l⁻¹) as carbon source, corn steep solid (10 g l⁻¹) as nitrogen source, and sea salt (15 g l⁻¹). The highest biomass, lipid, and DHA production of KRS101 upon fed-batch fermentation were 50.2 g l⁻¹ (16.7 g l⁻¹ day⁻¹), 21.8 g l⁻¹ (44% DCW), and 8.8 g l⁻¹ (40% TFA), respectively. Similar values were obtained when a cheap substrate like molasses, rather than glucose, was used as the carbon source (DCW of 52.44 g l⁻¹, lipid and DHA levels of 20.2 and 8.83 g l⁻¹, respectively), indicating that production of microbial oils containing high levels of DHA can be produced economically when the novel strain is used.

Matched MeSH terms: Glucose/metabolism
Withaferin A Protects Against High-Fat Diet-Induced Obesity Via Attenuation of Oxidative Stress, Inflammation, and Insulin Resistance

Abu Bakar MH, Azmi MN, Shariff KA, Tan JS

Appl Biochem Biotechnol, 2019 May;188(1):241-259.
PMID: 30417321 DOI: 10.1007/s12010-018-2920-2

Withaferin A (WA), a bioactive constituent derived from Withania somnifera plant, has been shown to exhibit many qualifying properties in attenuating several metabolic diseases. The current investigation sought to elucidate the protective mechanisms of WA (1.25 mg/kg/day) on pre-existing obese mice mediated by high-fat diet (HFD) for 12 weeks. Following dietary administration of WA, significant metabolic improvements in hepatic insulin sensitivity, adipocytokines with enhanced glucose tolerance were observed. The hepatic oxidative functions of obese mice treated with WA were improved via augmented antioxidant enzyme activities. The levels of serum pro-inflammatory cytokines and hepatic mRNA expressions of toll-like receptor (TLR4), nuclear factor κB (NF-κB), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand-receptor, and cyclooxygenase 2 (COX2) in HFD-induced obese mice were reduced. Mechanistically, WA increased hepatic mRNA expression of peroxisome proliferator-activated receptors (PPARs), cluster of differentiation 36 (CD36), fatty acid synthase (FAS), carnitine palmitoyltransferase 1 (CPT1), glucokinase (GCK), phosphofructokinase (PFK), and phosphoenolpyruvate carboxykinase (PCK1) that were associated with enhanced lipid and glucose metabolism. Taken together, these results indicate that WA exhibits protective effects against HFD-induced obesity through attenuation of hepatic inflammation, oxidative stress, and insulin resistance in mice.

Matched MeSH terms: Blood Glucose/metabolism
Aqueous calyxes extract of Roselle or Hibiscus sabdariffa Linn supplementation improves liver morphology in streptozotocin induced diabetic rats

Nazratun Nafizah AH, Budin SB, Zaryantey AH, Mariati AR, Santhana RL, Osman M, et al.

Arab J Gastroenterol, 2017 Mar;18(1):13-20.
PMID: 28336227 DOI: 10.1016/j.ajg.2017.02.001

BACKGROUND AND STUDY AIMS: The complex series of deleterious events among diabetes patients leads to multiple organ failure. Therefore, a holistic approach of treatment is urgently required to prevent worsening of complications. The present investigation was carried out to study the possible protective effects of Roselle or Hibiscus sabdariffa Linn (HSL) calyxes aqueous extract, as an antidiabetic and antioxidant agent against oxidative liver injury in streptozotocin-induced diabetic rats.
MATERIAL AND METHODS: A single dose of streptozotocin (45mg/kg body weight, iv) was used to induced diabetes in male Sprague Dawley rats which were then divided into two groups: Diabetic control (DC) and HSL-treated diabetic (DR) group. Normal rats were divided into normal control (NC), HSL-treated control (NR). Aqueous calyxes extract of HSL (100mg/kg/day, orally) was given for 28 consecutive days in the treated group. Weight, biochemical and histopathological (light and electron microscopic) parameters were compared in all groups.
RESULTS: Supplementation of HSL significantly lowered the level of fasting blood glucose and increased plasma insulin level in DR group compared to DC group (p<0.05). Alanine aminotransaminases and aspartate aminotransferase enzymes level were found to be significantly reduced in DR compared to DC. Microscopic examination demonstrated destruction of the liver architecture, cytoplasmic vacuolation of the hepatocytes and signs of necrosis in diabetic rats. Moreover, dilatation and congestion of blood vessels with leucocytes adherence were detected. Ultrastructural study using electron microscope showed homogeneous substance accumulation in nuclear chromatin, a decrease of organelles and mitochondrial degeneration in the diabetic rats.
CONCLUSION: Administration of HSL in diabetic rats causes significant decrease in hepatocyte destruction and prevented the changes associated with the diabetic condition. Thus, our findings provide a scientific rationale for the use of HSL as promising agent in preventing liver injury in diabetes.

Matched MeSH terms: Blood Glucose/metabolism

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